It turns out that after decades of studying the elements of rain's potential mood-boosting abilities, scientists have found some decent evidence to support it. And it's not the only benefit of rain: research shows rain also removes harmful substances from the air, while its unmistakable smell may even enhance our memories.

https://www.bbc.com/future/article/20260415-why-going-out-in-the-rain-gives-your-mood-and-brain-a-boost